Web turning device



B. JARREBY WEB TURNING DEVICE Filed March 18, 1964 Dec. 13, 1966 l Y, l

3.. lo F mvENroRi BERTIL JARREBY ATTYS- United States Patent O 3,290,795WEB TURNING DEVICE Bertil Jarrehy, Falkenberg, Sweden, assignor toAktiebolaget Svenska Flaktfahriken, Stockholm, Sweden Filed Mar. 18,1964, Ser. No. 353,031

Claims priority, application Sweden, Mar. 19, 1963,

5 Claims. (Cl. 34-122) The present invention relates to a web turningdevice for a web-like material and more particularly to a device for usein paper and cellulose dryers or similar treatment plants, wherein yaweb-like material is advanced in a number of passages having horizontal'and/or vertical lturns and is transmitted by means of the turningdevice from one passage to another. In the present instance the turningdevice comprises a cylinder having two axle spindles supported bystationary bearings. The web turning `device in a well known manner isdivided into two separate spaces with a perforated mantle surface andincluding means for the supply of a gaseous medium to the interior ofsaid device.

When drying or otherwise treating webs of, for example cellulose, paperor fabric it is known in order to save space, to conduct the web inzig-zag manner lthrough a treatment plant. Even if the web is carried bymeans of a series of endless transporting means or is advanced air-bornei.e. by means of a medium being blown towards the under-side of the web,there is a need for turning devices for transmitting the web from onetransporting plane to another. In order to-'facilitate the transmittingof the web from one transport plane to another during the Ithreading ofthe web, it is known to perforate the turning device and put it undervacuum so that the web is sucked to the `device and thus adheres to itas it turns. Experience has proved that by using a device of this designin instances where the treatment relates to thin, flimsy webs forinstance paper, to an unsuitable stretching strain results. To eliminatethis drawback air is supplied to the turning device, which air isdis-charged through the perforations yto create a friction diminishingair film between the device and the web. A primary object of theinvention is to make use of the last mentioned arrangement by providingimprovements in such web turning devices to permit automatic turning ofthe web during the threading of same.

The invention is characterized in that the two spaces of the device arelocated longitudinally of the web turning device, the perforations a-tone end of the device having depressed eye-lid shaped apertures to causevthe supplied medium to flow out in a tangential direction coincidentwith the rotational direction of the web turning device. Theseperforations lead to one of the above mentioned spaces located betweenthe surface and a tube inserted in the web turning device and having adiameter smaller than that of the device. In -addition means areprovided for the supply of gaseous medium to the limited space andhaving a higher pressure than that of the medium being supplied to theother space of the web turning device. The part of the device equippedwith eye-lid shaped apertures is located so that the web during normalrunning (during its transport) does not come in contact wi-th this partof the device, while during threading, the long narrow end (the tail) ofthe web bein-g advanced at the side of the proper transport plane,passes the web turning device above the eye-lid perforated part. Thetransport of the end (the tail) of the web may suitably take place bymeans of the arrangement disclosed in the U.S. patent to Wallin, Number3,206,092, issued on September 14, 1965. y

According to a suitable embodiment of the invention,

ICC

the end of the device which is perforated with eye-lid shaped aperturesprojects into a stationary chamber surrounding the projecting portionand providing a seal therefor. The chamber, iby means of a partition, isdivided into a high pressure chamber communicating with ythe closedspace provided with eye-lid shaped apertures, and a low-pressure chambercommunicating with the remaining part of the device by means of acylindrical, ported tube. The tube is inserted :into the device and.projects into the chamber past the above mentioned perforated end ofthe device thereby providing communication `with the low-pressurechamber by an opening having a packing ring and located in the partitionof the chamber. The part of the turning device being provided Withlowpressure medium may be perforated with relatively small round holesor may be provided with eye-lid shaped apertures.

Other objects and a fuller understanding of the invention may 'be had byreferring to the following specification and claims taken in conjunctionwith the accompanying drawing in which:

FIG. 1 is a fragmentary perspective view of a portion of a web turningdevice constructed in accordance with the .present invention;

. FIG. 2 shows a fragmentary perspective view of the above illustratedweb turning device connected to a chamber for the supply of gaseousmedium thereto, with a portion of the chamber broken away; and

FIG. 3 is an enlarged sectional view of the apparatus illustrated inFIG. 2.

In the drawing a web turning device 1 comprising a foraminous hollowcylinder 2 is supported by two spindles 3 and 4 `having connectingspiders 10 and mounted in stationary bearings (not shown). In accordancewith the invention the web turning device 1 is provided, at a threadingend 1a of the cylinder 2, with perforations, in the present instancedepressed eye-lid shaped apertures 5. The remaining surface of thedevice is provided with a plurality of medium discharge openings in theform of small, round holes 6. The depressed eye-lid shaped apertures 5communicate with a space 8 separated from the hollow central portion 7of the turning device. The radial boundaries of the space are definedlbetween the interior surface 8a of the cylinder 2 and a tube 9coaxially mounted therein, while a pair of spaced annular end walls 20and 21 define the axial boundaries of the space 48.

A chamber 11 surrounds a portion of the end 1a and by means of anannular .partition 12, is divided into a high-pressure portion 13communicating with the space 8 and a low-pressure portion 14,communicating with the interior 7 vof the cylinder 2. The tube 9inserted in the turning device is arranged to project into thelow-pressure portion 14 thus providing communication with the interior 7of the cylinder. An opening 15 provided with an annular packing ring 16is mounted in the partition 12 and seals `the low-pressure chamber 14,from the highpressure chamber 13. The high-pressure medium is suppliedto the high-pressure chamber 13 through an opening 17 while thelow-pressure medium is supplied to the chamber 14 through an opening 18.In order to insure an even distribution of the supplied medium, the tube9 may be extended along the whole length of the cylinder while beingprovided with medium distributing openings 19 in the low pressureportion of the device.

What is claimed is:

1. A turning device for web-like material, comprising 1n combination aforaminous rotatable, hollow cylinder having at least one spindlesupporting said cylinder, a tube mounted within said cylinder and spacedfrom the inner surface of said cylinder so as to define a longitudinalspace extending therebetween, at least one annular wall circumscribingsaid tube and connecting said tube to the inner surface of said cylinderso as to divide said space longitudinally into a rst and a secondchamber, said cylinder surface associated with said first chamber havinga plurality of means each defining an opening, said cylinder surfaceassociated with said second chamber having a plurality of holes therein,said openings positioned to cause a flow of a medium therethrough in adirection substantially tangential to the surface of said cylinder andin a direction coincident with the direction of intended motion of saidcylinder, said tube having a plurality of slots conned to the portion ofsaid tube associated Vwith said second chamber, means for supplying `alow pressure gaseous medium into said tu-'be through said slots, andmeans for supplying a higher pressure medin-m to said rst chamber.

2. A turning device in accordance with claim 1 wherein `at least some ofsaid openings comprise eye-lid shaped apertures, and said first chamberis positioned at one end ot said cylinder.

3. A turning device in accordance wit-h claim 2 including a stationarychamber positioned at said one end of said cylinder and enclosing aportion of said one end airtightly, and a partition airtightlycircumscribing said cylinder and mounted within said stationary chamberto form a high pressure chamber interiorly of said stationary chamberand circumscribing said portion.

4. A turning device in accordance with claim 1 wherein at least some ofsaid holes are eye-lid shaped apertures.

5. A turning device for web-like material, said device intended to lbeused in paper and cellulose dryers or similar treatment plants whereinthe web-like material is advanced in a number of passages withhorizontal or vertical turns and is transmitted by means of said turningdevice from one passage to another; said turning device comprising acylinder having a pair of spindle parts adapted to be supported bystationary bearings, said cylinder, in a manner known per se, beingdivided into at least two separate chambers with a perforatedcylindrical wall and with means for the supply of a gaseous medium tothe interior of said cylinder, said chambers of the cylinder beinglocated one after the other reckoned axially thereof; the perforationsof said cylinder at one end thereof being in the form of the pressedeye-lid shaped apertures to cause the supplied medium to flow out in atangential direction coincident with the moving direction of saidcylinder, said apertures leading to one of said chamlbers locatedbetween said surface of said cylinder and a tube inserted in saidcylinder, said tube having a smaller diameter than said cylinder, andmeans for the supply of a high pressure gaseous medium to said onechamber and means for the supply of a lower pressure gaseous medium tosaid other chamber of said cylinder.

References Cited by the Examiner UNITED STATES PATENTS 2,303,123 11/1942 Iohanessen. 2,825,979' 3/1958 Verwayen et al. 34--114 3,222,799 12/1965 Taylor 34-122 JAMES W. WESTHAVER, Primary Examiner.

1. A TURNING DEVICE FOR WEB-LIKE MATERIAL, COMPRISING IN COMBINATION AFORAMINOUS ROTATABLE, HOLLOW CYLINDER HAVING AT LEAST ONE SPINDLESUPPORTING SAID CYLINDER, A TUBE MOUNTED WITHIN SAID CYLINDER AND SPACEDFROM THE INNER SURFACE OF SAID CYLINDER SO AS TO DEFINE A LONGITUDINALSPACE EXTENDING THEREBETWEEN, AT LEAST ONE ANNULAR WALL CIRCUMSCRIBINGSAID TUBE AND CONNECTING SAID TUBE TO THE INNER SURFACE OF SAID CYLINDERSO AS TO DIVIDE SAID SPACE LONGITUDINALLY INTO A FIRST AND A SECONDCHAMBER, SAID CYLINDER SURFACE ASSOCIATED WITH SAID FIRST CHAMBER HAVINGA PLURALITY OF MEANS EACH DEFINING AN OPENING SAID CYLINDER SURFACEASSOCIATED WITH SAID SEOND CHAMBER HAVING A PLURALITY OF HOLES THEREIN,SAID OPENINGS POSITIONED TO CAUSE A FLOW OF A MEDIUM THERETHROUGH IN ADIRECTION SUBSTANTIALLY TANGENTIAL TO THE SURFACE OF SAID CYLINDER ANDIN A DIRECTION COINCIDENT WITH THE DIRECTION OF INTENDED MOTION OF SAIDCYLINDER, SAID TUBE HAVING A PLURALITY OF SLOTS CONFINED TO THE PORTIONOF SAID TUBE ASSOCIATED WITH SAID SECOND CHAMBER, MEANS FOR SUPPLYING ALOW PRESSURE GASEOUS MEDIUM INTO SAID TUBE THROUGH SAID SLOTS, AND MEANSFOR SUPPLYING A HIGHER PRESSURE MEDIUM TO SAID FIRST CHAMBER.